May-June 2013

Annual Tornado Summary 2012: A Fast Start and a Slow Finish

by Greg Carbin and Jared Guyer

One cannot adequately describe United States tornado activity in 2012 without first recalling the devastating tornadoes of 2011 (Weatherwise, May/June 2012). The most recent year provides an intriguing contrast to 2011 when the annual tornado count (1,690) was 148 percent of the 30-year normal (1,145), and the greatest number of tornado fatalities (553) occurred in the modern era. By comparison, 2012, with a preliminary count of 940 tornadoes, was nearly at the opposite end of the spectrum (82 percent of normal). This provides us with a dramatic example of how variable and unpredictable tornado activity can be from year to year, or even from one month to the next. There were intra-annual contrasts in 2012 tornadoes as well. The first few months of the year experienced well above normal tornado activity when compared to most of the remainder of the year. The running tornado count through April 2012 was nearly double the 30-year normal (496 tornadoes through April compared to a 30 year average of 286). In contrast, the months of May and June, historically the most active months, were conspicuously quiet.